Method of forming engine mountings



I March 30, 1948- R. A. KROPP} 2,433,384 I METHOD OF FORMING ENGINE MOUNTINGS Fileld Nov; 20, 194:5 '7' Sheets-Sheet 1 v izver z z o'r of 15 70 72 March 30, 1948. R. A. KRoPP ,4 IETHOD 0F FORIING ENGINE IOUNTINGS Filed Nov.'20, 194s 7'Sheets-'-Sl 1eet 2 March 30, 1948. R. A. KROPP METHOD OF FORMING ENGINE MOUNTIHGS 7 Sheets-She et a Filed Nov. 20, 1943 iwwzfr fiqy of Kiwi/ 30, R, A. KROPP METHOD OF FORMING ENGINE MOUNTINGS F i1ad Nov. 20, 194;: V '7 Sheets-Sheet 4 Fly/4 i jie enfar March 30, 1948. I KROPP 2,438,884

METHOD OF FORMING ENGINE MOUNTINGS Filed Nov. 20, 1948 7 Sheets-Sheet s I 50 4 fna'enzor 4 8..- lal/fi @119 fw MWQHB 3% 1948. KROPP 2,43%,884-

METHOD OF FORMING ENGINE MOUNTINGS Filed NOV. 20, 1943 7 Sheets-Sheet fifyaf 1% "0 7 Jflarmqy Malfch 30, 1948. R. A. KRoPP 2,438,884

METHOD OF FORMING ENGINE MOUNT'INGS Filed Nov. 20, 1945 7 Sheets-Sheet 7 Patented Mar. 30, 1948 Roy A. Kropn, mm norm, in.

aulgnor to Krupp Forge Aviation 00., (lieu-0,111., a corporation of Illinois Application 1 This invention relates to improvements in engine mountings, particularly mountings for airplane engines. More particularly, the invention relates to the methodof forming-an airplane engine mounting ring, preferably made in two sections, although it may be made in a greater numher of sections, or in one piece.

Heretofore, engine mountings of the radial engine type have been made largely of tubing, but this type mounting has been attended by numerous disadvantages. The mounting of my design has advantagesover other mountings in thatit has much greater strength and it does not require near as much welding, nor need the welding be done by expert welders. The mounting formed by this method is lower in cost and may be made much faster than the prior mountings, and the problems of repair are simpler and less frequent. It will be manifest that the fewer the parts of the engine mounting ring, the less work there will be in welding, straightenin checking, etc.

Further objects and advantages will appear and be brought out more fully in the following specification, reference being hadto the accompanying drawings in which:

Fig. 1 is an elevational viewoi the stock as-received, before it is worked on, showing the tongue to be grasped by the tongs.

Fig. 2 is an end view of the same.

Fig. 8 is an elevational view of the same, after it has been roughly forged by the preforming and stretching die, as shown in the bottom section of the triple composite die shown in Fig. 14.

Fig, 4 is an elevational view of the rough forging as .it'appears after it has been worked upon. by the middle section of the triple composite die in Fig. 14.

Fig. 5 is a sectional view of the forging, taken on the line 5-5 of Fig. 4.

Fig. 6 is a plan view of the forging, after it has been worked upon by the top or bending section of the triple composite die of Fig. 14.

It will be understood that Fig. 14 shows the lower section of the triple composite die and that there is a corresponding upper section, shown in Figs. 15 and 20.

Fig. '7 is a plan view of the forging and flashing produced by the blocking die, shown in Fig. 16; this being the lower section of the die, the upper section is shown in Fig. 21.

Fig. 8 shows the forging of Fig. 7, with the flashing removed by the trimming die shown in Fig, 18, the upper section of which is shown in Fig. 22.

Fig. 9 shows November 20, 194 Seth! No. 511,078

3 Claims. (cries-o) by the finishing die, which is similar to the preforming or blocking die shown in Fig. 16, except that in general it is designed to thin the parts, including the webs of the forging after it has left the blocking die 4| and the trimming die It; the

'ilnish'ing die being shown in Figs. 23 and 24.

Fig. 10 shows the sameiorging as in Fig. 9, with the flashing removed by the trimming die,

Fig. 11 is an end elevation of the forging shown in Fig. 10.

Fig. 12 is an enlarged sectional view taken on theline lI-II ofFlg. 10. p

Fig. 13 is an enlarged sectional view taken on the line "-43 of Fig. 10, showing one of the bosses.

Fig. 14 is a plan view of a triple composite die, the lower section showing thepreforming and stretching die used to produce the rough forging of Fig. 3. The upper section of the triple composite 'die is shown in Fig. 20. The middle section of the triple composite die of Fig. 14 shows the part used to produce the forging of Fig. 4; the

upper part of the triple composite die showing the bending section used to produce the rough forging of Fig. 6. i

Fig. 15 is an elevational view showing the upper and lower sections of the triple composite die, the lower section of which is illustrated in Fig. 14, with some of the parts shown in dotted lines.

Fig. 16 is a plan view of the bottom section of the blocking die used to produce the forging and flashing of Fig. 7, the upper section being shown in Fig. 21.

Fig, 17 is a sectional view of the upper and lower sections of the blocking die, taken on the line i'l-l'l of Fig. 16; the blocking die being shown in Figs. 16 and 21.

Fig. 18 is a plan .view of the lower section of the trimming die used to trim the flashing of! the forging shown in Fig. 7 to produce the forging shown in Fig. 18. The same die as shown in Fig.

18 is used to trim the flashing ed the finished forging shown in Fig. 9 after that forging has left the finishing die. The upper half of the trimming die is shown in Fig. 22.

Fig. l9ris a sectional view taken on the line l9l9 of Fig. 18, showing a section of the trimming die.

Fig. 20 is a view looking up at the upper section or the triple composite die, the lower section of which is shown in Fig. 14,

Fig. 21 is a plan view of the upper section of the blocking die, the lower section of which is showninl'ig. 16.

the forging and produced 1 Fig. 22 is a plan view of the upper section 0! showninl'lg. 18.

the trimming die, the lower section of which is Fig.723 is a plan view of the the finishing die; and I Fig. 24 is a plan view of the upper section of the finishing die.

1 Referring more particularly to the drawings to lower section of illustrate the construction and method of the preferred form of my invention, the drawings show in Fig. 1 the rough'stock 23, which is'used to make a forging, and which may be provided with a tongue 28 for assistance in the handling of the stock by the operator, who uses tongs to withdraw the stock from the furnace after it has been suillciently heated.

- The stock 25 is then applied to a triple com posite die 21, which in reality combines three dies, and is shown clearly in Figs. 14, and 20. Taking Fig. 14, for example, the bottom section 28 of the triple composite die is a preiorming and stretching die; the middle section 28 is a rolling die, and the top section 33 is a bending die.

The preforming and stretching die 28, as shown in Figs. 14 and 15 comprises recesses 3| and raised portions 32, which are concaved, as shown at 33. In the use of the preforming and stretch- Y 7 ing die. 28, the operator works a steam hammer to stamp out reduced portions, thereby producing enlarged portions 34, as shown in Fig. 3, which form the bases for bosses to be hereinafter described.

After this operation, the rough forging 35, as

"shown in Fig. 3, is placed in the rolling die 23,

which is comprised of recess portions 36 and other deeper recess portions 31, which are ordinarily "six in number, corresponding to the six bosses to be provided on the standard engine mounting,

- two of which are actually twin angular pairs of bosses. The rough forging 35 is then worked in the rolling die 29 to. produce the rough forging 35a, shown in Fig. 4, and in section in Fig. 5. The

' rolling die 29 renders the rough forging into the form shown in Figs. 4 and 5, .the stock being rolled about in'said rolling die by the operator until the proper rough shape is obtained, as will I be readily understood by those skilled in the art.

It will, thus, be seen that the rough forging advances one step nearer its eventual shape, as showninFig, 10. r L

In the next operation, the rough forging 35a is worked upon in the bending die 3ll,'as shownin Figs. 14, 15, 20, and other views. The bending die has an upper section 38 and a, lower section 38, as do all the other dies: the upper section 38 having recesses 40 corresponding to the enlargements on the rough forging a. The

general shape of the lower section 39 is, semi-circular, and the general shape of the upper section 38 is somewhat similar, except that it is naturally smaller and has the recesses 40 afore- V I mentioned.

The rough forging 35a is then worked between the sections 38 and 39 of the bending die 30 to PI'OdlCe the rough bent forging 35b, shown in Fig. I A

In the next step of the operation, the rough forging 35b is'taken to the blocking die ll, of which the lower section is shown in Fig. 16. This section comprises a flashing recess 42 and deeper recesses 43 and 44 in which the metal is stamped or forged. There are, also, raised portions 45 to form the grooves of the forging, as may be readily understood by those skilled in the art. The upper section 48 of the blocking die 4!, will, of I course, be similar to the lower section M in con- 7 forth, but desire to avail myself of such variations the invention.

struction. according to the common practice in providing male and female dies, as in Fig. 21, expt that there will be no recesses for the angular bosses 31 in the upper die, but only a smooth web instead.

After the rough forging 35b is worked in the blocking die ll, there results the forging Me, with the flashing 41. The forging 33c is then taken to the trimming die 48, the lower section of which is shown in Fig. 18. which has a raised portion 48 and a recess 38.. It will be understood that the upper section of the trimming die 48 will be'as shown in Fig, 22.

After the rough forging 380. has been worked in the trimming die, the flashing 41 is trimmed of! and there results the forging 35d, shown in Fig. 8. After this operation, the forging 38d is taken to the finishing die 5!, which is similar to,

the blocking die, the lower section of which is shown in Fig, 16. The function of the finishing die is to round oil. the forging still more, and to thin the parts, including the web. The construction of the finishing die 5| is slightly changed in dimensions only to effect such changes. The lower section of the finishing die 5| is shown in Fig. 28 andv the upper section is shown in Fig. 24.

Both sections of .the finishing die 5| have a flashing recess 42a and deeper recesses 43a and a in which the metal is further forged. One

difference which exists between the upper and lower sections oi.v the finishing die is that the upper section, shown in Fig. 24, does not contain the recesses for the angular bosses 51, as does the lower section of the finishing die, shown in Fig. 23, the angular bosses being only on one side of the forging. Raised portions 45a. are provided on the finishing die to form the grooves of the for in After the forging 35d has been worked on in the finishing die, then there'results the forging 35c, which, also, has a flashing integral with it. This flashing is trimmed off again as before; Fig. 10 clearly shows the forging as it appears when the forging is finally completed.-

, The forging35e hasan outer rim 52, an inner rim 53, web portions 54, ribs 55, bosses 56, an- A The forging may, also, be sandblasted for twenty minutes, although this time may be varied. The for ing may, then, be m nafluxed and checked for straightening. v

The stock used at the outset to wit: preferably two and one-half inch round stock,uthirty-nine and one-half inches long, has proven satisfactory. The advantages of this type of construction will be manifest to those-skilled in the art. As a matter of fact, this construction has supplanted tubular construction heretofore used in the United States bombers.

While I have illustrated and described the preferred form of construction for carrying my invention into effect, this is capable of variation and modification without departing from the spiritof I, therefore, do not wish to be limited to the precise details of construction set for this purpose, I

and modifications as come within the scope of the appended claims.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is:

1. A method oi! forming an airplane engine mounting which omprises thinning a bar stock at certain predetermined points; die forging the piece to more accurately form enlarged portions left by the thinning step; bending the piece into a semi-circular shape; die forging the bent piece to form an H cross-section and to form bosses and enlarged end flanges from the enlarged portions; and welding a plurality. of sections thus formed at their end flanges to form a ring.

2. A method of forming an airplane engine mounting which comprises thinning at predetermined points a bar stock of a diameter at least as great as the largest portion of the finished mounting; die forging the piece to more accurately form the enlarged portions remaining after 'the thinning operation; said enlarged portions being so formed as to anticipate deformation in the subsequent bending; bending the piece into a semi-circular shape utilizing the enlarged portions, die forging the bent piece to form an H cross-section and the form bosses and en.- larged end flanges from the enlarged portions; trimming the flash therefrom; die forging again to more accurate dimensions; again trimming the flash; and welding together a plurality of sections thus formed into a ring by means of the end flanges thereon. 3. A method of formingan airplane engin mounting which comprises rough forging a bar 6 stock so as to thin it at predetermined points and to leave spaced rough enlarged portions; rollingv the piece in a rolling die tomore accurately form the enlarged portions; bending the piece into a semi-circular shape by means of a bending die, further forging the bent piece in a blocking die to form an H cross-section and to form bosses and enlarged end flanges from the enlarged portions; trimming the flash therefrom in a trimming die;

again forging in a finishing die to more accurate dimensions; again trimming oil! the: flash; and welding a plurality of sections thus formed into a ring by means of the end flanges.

. ROY A. KROPP.

REFERENCES CITED The following references are of record in the file of this patent:

I UNITED STATES PATENTS Number 

